BUTTE, the largest city of Montana, U.S.A., and the county-seat of Silver Bow county. It is situated in the valley of Deer Lodge river, near its head, at an altitude of about 5700 ft. Pop. (1880) 3363; (1890) 10,723; (1900) 30,470, of whom 10,210 were foreign-born, including 2474 Irish, 1518 English-Canadians, and 1505 English; (1910 census) 39,165. It is served by the Great Northern, the Northern Pacific, the Chicago, Milwaukee & Puget Sound, the Butte, Anaconda & Pacific, and the Oregon Short Line railways. Popularly the name “Butte” is applied to an area which embraces the city, Centerville, Walkerville, East Butte, South Butte and Williamsburg. These together form one large and more or less compact city. Butte lies in the centre of the greatest copper-mining district in the world; the surrounding hills are honey-combed with mines, and some mines are in the very heart of the city itself. The best known of the copper mines is the Anaconda. The annual output of copper from the Butte district almost equals that from all the rest of the country together; the annual value of copper, gold and silver aggregates more than $60,000,000. Although mining and its allied industries of quartz crushing and smelting dominate all other industries in the place, there are also foundries and machine shops, iron-works, tile factories, breweries and extensive planing mills. Electricity, used in the mines particularly, is brought to Butte from Cañon Ferry, 75 m. to the N.; from the plant, also on the Missouri river, of the Helena Power Transmission Company, which has a great steel dam 85 ft. high and 630 ft. long across the river, and a 6000-h.p. substation in Butte; and from the plant of the Madison River Power Company, on Madison river 71/2 m. S.E. of Norris, whence power is also transmitted to Bozeman and Belgrade, Gallatin county, to Ruby, Madison county, and to the Greene-Campbell mine near Whitehall, Jefferson county. In 1910 Butte had only one large smelter, and the smoke nuisance was thus abated. The city is the seat of the Montana School of Mines (1900), and has a state industrial school, a high school and a public library (rebuilt in 1906 after a fire) with more than 32,000 volumes. The city hall, Federal building and Silver Bow county court house are among the principal buildings. Butte was first settled as a placer mining camp in 1864. It was platted in 1866; its population in 1870 was only 241, and for many years its growth was slow. Prosperity came, however, with the introduction of quartz mining in 1875, and in 1879 a city charter was granted. In the decade from 1890 to 1900 Butte's increase in population was 184.2%.